Vat dyestuff



Patented Feb. 25, 1941 UNITED STATES PATENT OFFICE VAT D'YESTUFF Maurice H. Fleysher, Buffalo, N. Y., assignor to National Aniline & Chemical Company, Inc., New York, N. Y., a corporation of New York No Drawing. Application April 12, 1938, Serial No. 201,491

3 Claims. (Cl. 260316) This invention relates to a new and useful vat to black shades which are very fast to chlorine,

dyestufi dyeing cotton gray to black shades. light, washing, and boiling alkali.

It relates more particularly -to a vat dyestuff Example 2.A mixture of 290 parts of spewhich is derived from a certain di-anthraquinocially denatured alcohol (U. S. specially denylimino-dibenzanthrone, namely, the di-(l-annatured alcohol Formula 2B) and 1120 parts of thraquinonylimino) dibenzanthrone resulting caustic potash was heated to about 160, and to from the condensation of two molecular proporthe agitated molten mass, 263 parts of the ditions of l-aminoanthraquinone with one molecu- (l-anthraquinonylimino) dibenzanthrone were lar proportion of the dibrom-dibenzanthrone added in small portions at frequent intervals over which is obtained by brominating dibenzanthrone a period of about 2 hours. The mass was agiin chlorsulfonic acid with bromine in the prestated at about 170 for an additional 1% to 2 ence of a small amount of a halogen carrier, hours, after the last addition of dibenzanthrone such as sulfur or iodine. compound was made. The resulting fusion mass According to the present invention a vat dyewas drowned in about 10,000 to about 11,000 parts stuff dyeing cotton greenish-gray to reddish-gray of water and the aqueous mixture was treated to black shades which are fast to chlorine, light, thereafter in the manner described in Example 1.

washing and boiling alkali, is obtained by heat- The product of this example has the same ing said di-(l-anthraquinonylimino) -dibenzanphysical and dyeing characteristics as the prodthrone with a condensing agent of the type uct of Example 1.

usually employed for converting a dianthrimide Example 3.675 parts of anhydrous aluminum 20 to a carbazole compound. chloride .and 225 parts of dry common salt were The processes whereby said di-(l-anthraquinoheated and agitated to form a uniform fused nylimino)-dibenzanthrone can be converted to mass. To the resulting fused mixture maintained the vat dye of this invention are illustrated by between 150 and 155, 150 parts of the di-(lthe following examples in which the parts are by anthraquinonylimino) dibenzanthrone w e r e 25 weight and the temperatures are in degrees added at frequent intervals and in small portions. centigrade. The mixture was agitated and maintained be- Eatatmple 1.--A mixture of 400 parts of caustic tween 150 and 155 for about one-half hour otash and 25 parts of water was agitated and after the last addition of imino compound; then heated toobtain a uniform liquid mass at a temthe reaction mass was transferred to about 7000 30 perature between 230 and 240. To this agiparts of cold water containing about 250 parts tated mass, 30 parts of the di-(l-anthraquinonylof 66 B. sulfuric acid. The aqueous mass was iminoi-dibenzanthrone were added and the mixboiled un il l umpy m terial therein was comture was agitated and maintained between 230 pl ly in r T e nely divided olid and 240 for about 1 hour. The fused mass was mate ia was s a a d as a a by fi t a s5 r ned in about 4000 parts of water, while the and washed with water until it was free of acid.

temperature of the aqueous drowned mass was The Cake Was dried in an ovene d y not allowed to rise above 75. The aqueous mixdyestuff was dissolved in .10 times its weight of ture was aerated between 50 and 75 tooxidize Sulfuric a d d t e S ut on Was the leuco form of the fusion product therein to dr wne in Water heated to about 60 and weigho the desired product, and the whole mass was ns about 3 times th We ht of the dissolved then made slightly acid by the addition of suldyeStu The aqueous mass was diluted further furic acid. The precipitated dyestuff was sepawith water, and the precipitated dyestufi was rated as a cake by filtration of the aqueous acid separated by filtration as a cake which was mass, and was washed acid-free with water. washed with water until it was free of acid. 45

The product, when dried and ground, is a jet The product, When dried and ground, s a j black powder which is insoluble in water. It black p de W c is insoluble in water. It is .dissolves in nitrobenzene to form a green solusoluble in concentrated sulfuric acid to form a tion which has a strong reddish fluorescence. It-s violet-black solution which assumes an olive 5 solution in aniline is olive green. It dissolves in shade when a few drops of nitric acid are added concentrated sulfuric acid to form a violet-black thereto. 'A solution of the product in nitrobensolution, which, upon addition thereto of a few zene is dull violet and is characterized by a very drops of nitric acid, is converted to a clear green strong reddish fluorescence. Its solution in solution. From a hydrosulfite vat, which .is aniline is "dull red-violet. From vats whichpare violet-red, it dyes cotton excellent greenish-gray reddish-blue, it "dyes" cotton .:exce1lent 'reddish- .55

gray to black shades which are very fast to chlorine, light, and washing. It is well adapted for dyeing and printing by the usual methods.

The'vat dye product of the present invention has the additional desirable property of forming mixtures with other vat dyes, whereby the shade of the resulting dyeings obtained with said product may be modified. Thus, it may be mixed with the orange dyestuff, dibrom pyranthrone; the khaki dyestuff, carbazolized 1,4,5,8-tetra-anthraquinonylimino-anthraquinone; and/or the brown dyestuif produced by carbazolizing the condensation product obtained from l-benzoylamino-5 chloranthraquinone and 1 benzoylamino 4- chloranthraquinone, in various proportions to produce mixtures useful in the usual dyeing and printing processes to produce dyeings and prints varying from red-black to jet-black to greenblack shades.

The filter-cakes resulting from the processes of the above examples can be admixed in the usual manner with dispersing agents, diluents, etc., and thus incorporated into vat dye pastes of standard strength, or then dried, ground and, standardized in powder form.

It will be realized by those skilled in the art that the invention is not limited to the details of the above illustrative examples and that changes may be made without departing from the scope of the invention.

Thus the conditions and the manner of treatment may be varied, depending on the particular form in which the product is desired. If the black vat dye of the present invention is desired in the form producing dyeings having a greenish cast, the heating of the d'l-(l-anthraquinonylimino)-dibenzanthrone is preferably carried out with an alkaline condensing agent; whereas if the vat dye is desired in the form producing dyeings having a reddish cast, the heating of said di-(l-anthraquinonylimino)-dibenzanthrone is preferably carried out with an acid condensing agent. Presumably the color of the dyeings is influenced to some extent by the nature of by-products present in the final product, which differ somewhat among themselves depending on the specific conditions of the treatment. Instead of the condensing agents employed in the above examples, other condensing agents of the type usually employed for the conversion of a dianthrimide to a carbazole compound can be used, a number of which are known in the art; for example, sodium hydroxide, a mixture of sodium hydroxide and potassium hydroxide, sodium or potassium anilide and sodium or potassium amide.

The presence of sodium chloride in the fusion mixture in Example 3 is not essential but it is preferred inasmuch as it results in a lower fusion temperature, thereby resulting in a purer product than is obtained at higher temperatures. Instead of sodium chloride, other fiuxing agents may be employed; such as antimony trichloride, pyridine, urea, etc.

The extent to which the heating is carried out will vary with the condensing agent and temperature employed, as is usual in condensation reactions of this type. For example, in the process of Example 2, formation of the desired product ordinarily will be found to be complete at to C. when the fusion mass is maintained at 160 to 180 C. for from 1 to 2 hours after the addition of intermediates to the fusion mass.

The oxidation of the leuco compound present in the fusion mass resulting from the condensation in Examples 1 and 2 can be effected in various ways, as will be evident to those skilled in the art of making vat dyes.

The acid pasting of the product forming a part of the procedure of Example 3 may be omitted, although acid pasting is preferably carried out in view of the superior purity and form of the product resulting therefrom. Moreover, other methods of acid pasting known to the art may be employed; although the procedure involving partial dilution of the sulfuric acid solution of the dyestuif with warm water, followed by further dilution, as set out in Example 3, is preferred in view of the desirable physical form of the product resulting therefrom. If desired, the products resulting from the use of other condensing agents (as for example, the products of Examples 1 and 2), also may be subjected to an acid pasting procedure.

If desired, the product may be subjected to an oxidation after-treatment in an acid or alkaline medium, either before or after it has been acid pasted, as described in Example 3. Thus the wet cake of dyestuff may be suspended in water at about 50 to 60 C. and treated for about 1 hour, in the presence of weak alkali with small amounts of hydrogen peroxide or alkali-metal hypochlorites, perborates and persulfates, or in the presence of weak acid with small amounts of nitrites, alkali-metal chromates and bichromates, etc.

While the nature of the product of the present invention is not known, it is believed that the heat treatment with the condensing agent results in a condensation between the dibenzanthrone nucleus and the two anthraquinone nuclei of the di 1 anthraquinonylimino) dibenzanthrone, with elimination of 4 atoms of hydrogen and formation of heterocyclic nuclei including the imino nitrogen atoms, possibly of the carbazole type. The invention is not limited, however, to any theoretical explanations.

The nature of the di-(l-anthraquinonylimino)-dibenzanthrone employed as starting material for the production of the vat dyestuff of the present invention is an important factor in the production of a vat dye having the desirable properties of the product of the present invention, the di-(l-anthraquinonylimino) -dibenzanthrone employed in accordance with the present invention being that resulting from the condensation of two molecular proportions of l-aminoanthraquinone with one molecular proportion of the dibrom-dibenzanthrone which results from the bromination of dibenzanthrone in chlorsulfonic acid with bromine in the presence of a small amount of a halogen carrier, such as sulfur or iodine. The reason for this fact is not definitely known but it is believed that the orientation of the bromine atoms with respect to the dibenzanthrone molecule as a result of the method of preparation, and the consequent orientation of the iminoanthraquinone radicals produced therefrom are important factors.

The method by which the said dibrom-dibenzanthrone is condensed with the l-aminoanthraquinone for the production of the starting material of the process of the present invention is not limited to any specific conditions other than those known to the art for the preparation of said product. In general, it involves heating at least two molecular proportions of l-aminoanthraquinone with one molecular proportion of said dibrom-dibenzanthrone is a suitable solvent (for example, nitrobenzene or naphthalene) in the presence of an acid binding agent (for example, 75

sodium carbonate) and of an amination catalyst (for example, copper carbonate).

I claim:

1. A vat dyestufi prepared by heating with a condensing agent adapted to convert a dianthrimide to a carbazole compound the di-anthraquinonylimino dibenzanthrone resulting from the condensation of two mols of alpha-amino-anthraquino-ne with one mol of the di-brom dibenzanthrone prepared by brominating dibenzanthrone in chlorsulfonic acid in the presence of a halogen carrier, said dyestufi being in the dry, ground form a black powder insoluble in water, soluble in concentrated sulfuric acid to form a violet-black solution, soluble in nitrobenzene and aniline, and dyeing cotton from a hydrosulflte vat gray to black shades which are fast to chlorine, light, washing and boiling alkali.

2. A dibenzanthrone vat dyestufi which in the dry, ground form is a black powder, giving in nitrobenzene a green solution with strong reddish fluorescence, in aniline an olive green solution, in

concentrated sulfuric acid a violet-black solution which on adding a few drops of nitric acid turns clear green, dyeing cotton fast greenish-gray to black shades from a violet-red vat and resulting from a caustic alkali fusion of the di-anthraquinonylimino dibenzanthrone obtained by brominating dibenzanthrone in chlorsulfonic acid in the presence oi a halogen carrier and condensing the resultant dibrom dibenzanthrone with two mols of alpha-amino-anthraquinone for each mol of dibrom-dibenzanthrone.

3. A dibenzanthrone vat dyestufi which in the dry, ground form is a black powder, giving in nitrobenzene a dull violet solution with strong reddish fluorescence, in aniline a dull reddishviolet solution in concentrated sulfuric acid a. violet-black solution which assumes an olive shade on addition of a, few drops of nitric acid, dyeing cotton fast reddish-gray to black shades from a reddish-blue vat and resulting from an aluminum chloride fusion of the di-anthraquinonylimino dibenzanthrone obtained by brominating dibenzanthrone in chlorsulfonic acid in the presence of a halogen carrier and condensing the resultant dibrom-dibenzanthrone with two mols of alpha-aminoanthraquinone for each mol of dibrom dibenzanthrone.

MAURICE H. FLEYSHER. 

